Apparatus for producing printing plates



March 22, 1938. l. BRIMBERG 2,112,010

APPARATUS FOR PRODUCING PRINTING PLATES Fi led Oct. 28, 1929 V IVENTOR. 4,4, (3W I BY I A TTORNE Y.

Patented Mar. 22, 1938 UNITED STATES PATENT OFFICE Isaac Brimberg, Brooklyn, N. Y. Application October 28, 1929, Serial No. 402,963

12 Claims.

This invention relates'to a novel method of an apparatus for making black and white or colored half-tone pictures in such a manner as to eliminate the'steps of engraving and etching in the making of half-tone plates for newspapers.

In half-tone pictures as now made and in the making of newspaper pictures they are formed with a series of black dots on white areas and in the darker portions of the picture are white dots in, black areas and graduations from a round black dot to a round white dot causes the black dot to have more of a square contour.

In accordance with this invention half-tones are produced by providing a variable dot frequency. In other words, in the white portions are dots which are widely spaced and in the dark portions the dots are very close to each other. In order to produce such result these dots are, not

round but preferably form a square with inden tations in each side. This square arrangement of the dots enables one to obtain a denser black.

The dot.former consists of a needle or tool having its operative end in the form of a square with tits sides slightly indented, or any other desired shape that will make a good half or medium tone picture or plate.

If the dot forming needle is insulated from the drum and a paper or sheet impregnated with a substance which will change color upon the passage of current instead of using a softened metal to receive the picture then facsimile reproductions can be made in half-tone or any other picture and even a black and white picture can be reproduced. In accordance with my present invention a point of light is transmitted through a film into a photoelectric cell. The metal in the receiving end is preferably formed by a pulsating dot former instead of by a machine tool so that it is formed by indenting in contradistinction to cutting. The metal plate should be slightly softened.

When facsimiles are reproduced, as above set forth, synchronization is used between the transmitter and the receiver so that pictures can be sent by-wireless or any other means of communication.

A further object of the invention is to devise a novel machine wherein by increasing its speed a lighter picture can be received because the dots become further spaced from each other.

A further object of the invention is to regulate I the depth of the dots by varying the output level of the last amplified stage. 55 A further object of the invention is to control the number of dots per inch by varying the frequency of the oscillator, it being understood that one is not limited in any way to the frequency of the oscillator or the frequency for light or dark portions of the picture. Other novel features of construction and advantage and objects of the invention will hereinafter more clearly appear in the detailed description and the appended claims.

With the foregoing in view, my invention com- 10 prehends a novel method of and apparatus for producing facsimiles, and plates for printing pictures in any desired color, and pictures and plates resulting from such method. v

It further comprehends a novel method and 15 apparatus for making a printing plate having varying dot frequencies.

It further comprehends a novel method of making half-tone pictures on metal or mat. i

It further comprehends a. novel method of 20 making half-tone pictures in colors. containing one or more colors.

It further comprehends a novel method and apparatus which eliminates the use of engraving and etching in newspaper reproduction of pic- 25 tures having any type of tone, half-tone or black and white.

It further comprehends a novel method and apparatus for facsimile picture transmission.

It further comprehends a novel dot former and 30 novel means for actuating it.

The invention further comprehends a number of novel featureswhich will hereinafter be clearly set forth.

For the purpose of illustrating the invention, 35 I have shown in the accompanying drawing a typical embodiment of it, which, in practice, will give reliable and satisfactory results. It is, how.- ever, to be understood that this embodiment is typical only and that the various instrumentali- 40 ties of which my invention consists can be variously arranged and organized, and the invention is not limited to the precise arrangement and organization of these instrumentalities as herein set forth. 4,5

Figure 1 is an electrical diagram illustrative of a mechanism which can be employed in carrying out my invention.

Figure 2 is a sectional elevation of a machine which can be employed in carrying out the invention, the illustration being partly diagrammatic.

Similar numerals of reference indicate correspondins Darts.

Referring to the drawing:

Referring first to the electrical diagram seen in Figure 1, l designates a light source which is movable into a cylinder 2 which carries the film 3 so that the light passing through the film 3 causes a varying direct current in the photoelectric cell 4. These pulsations of the direct current are amplified by the photoelectric cell amplifier 5. The output current of this amplifier 5 causes a varying current to flow in the coil 6 thereby actuating a plunger 1 and causing the frequency of the coil circuit 8 associated with the vacuum tube 9 to vary in period depending upon the inductive variation of the coil 8. This fluctuated frequency is amplified by any desirable type of amplifier i0. Theoutput of the amplifier ill actuates the needle or tool ll of the dot impressor l2.

The needle H forms the dots by indenting or marking a metal paper or other receiver l3 carried by a revoluble support 14.

Referring now more particularly to Figure 2, I5 is a base having a groove IE to receive a slide I! which is moved by means of a shaft I8 of a synchronous motor l9 fixed to the base IS. The light source I is movable under the film 3 and one or more photoelectric cells 20 are employed carried by a bar 2| connected with the slide I1. This bar is indicated as being separated as at 22 for remote synchronization.

23 is a panchromatic filter which may be employed if desired. The shaft i8 is grooved as at 24, for example, the grooves may be about sixty to the inch, to cause the travel of the guide 25 fixed to the bar 2| on which is also mounted the photoelectric cell 20 and the dot impressor I 2. As before explained the amplified varying current from the photoelectric cell 4 goes into the coil 6 and varies the distance the plunger 1 goes into the primary coil 26 of the oscillator 9; or, the amplified varying current from cell 4 goes into coil 6 and varies the degree of magnetic saturation of the plunger 1, thus varying the inductance of the coil 26 and varying the frequency of the oscillator 9. This oscillator is a pure electric wave oscillator of sixty to three hundred or more cycles per second preferably. This varying frequency at constant output of the oscillator varies the number of dots per inch impinged on the metal plate or paper mat l3. From this mat a plate for a half-tone printing can be made.

If four photo cells are employed each having its oscillating and amplifying circuits as shown in Figure 1, four color plates can be made simultaneously.

By placing photoelectric cells around the periphery of the transmitting drum 2 associated with the light i and by employing suitable panchromatic filters 23 with each associated photoelectric cell, a plate can be produced simultaneously in half-tone for one or more colors. Each cell will have associated with it its cellamplifier, variable plunger, oscillator, amplifier, and dot impressor.

Thus for each color a half-tone impression in metal or any other material can be produced. After removing each of these impressions from the receiving drum or plate they can be inked with their proper color, and then superimposed one on the other to print a picture in rich halftone colors or any other desired color combination.

If the receiving mat is impregnated with a substance which will change color upon the passage of current, and voltage is applied between the needle I l'of the dot impressor and the cylinder l4, facsimile work can be produced.

This invention is'not limited to the shape or form of the transmitting head which may be cylinder as shown, or a flat plate holder, keeping in mind however that the transmitter and the receiver must be run in synchronism.

The picture received is not limited to metal or paper but may be impinged on any desired material, such as leather, stencil paper or wood or any other devices for picture reproduction. The light can be located either inside the transmitter drum or film holder or exterior of it and the same holds true of the photoelectric cell.

By increasing the speed of the rotating machine a lighter picture can be produced as the dots become further spaced.

The depth to which the dots are formed can be regulated by varying the output level of the last stage of amplification.

The number of dots per inch are controlled by varying the frequency of the oscillator.

It will be clear that in accordance with this invention one is not limited in any way to the frequency of the oscillator or the frequency for the light or dark portions of the picture.

In so far as I am aware I am the first in the art to devise the method herein set forth or to make a plate having a varying dot frequency and printed in any desired'color or colors or to reproduce for transmission by wireless or any other means of communication, pictures as herein made, and its is therefore to be understood that I desire my claims to such features to receive the broad and generic interpretation to which a pioneer in the art is entitled.

It will now be apparent that I have devised a new and useful method of and apparatus for producing facsimiles and plates for printing pictures in any desired color, and pictures and plates resulting from such method, which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description and while I have, in the present instance shown and described a preferred embodiment thereof which will give in practice satisfactory and reliable results it is to be understood that this embodiment is susceptible of modification in various particulars without departing from the spirit or scope of the invention or sacrificing any of its advantages.

Having, thus described my invention What I claim -as new and desire to secure by Letters Patent, is:

1. Anapparatus for making half-tone printing plates or engravings, comprising means to scan a picture or negative by light, means to translate the picture shadings into electrical pulsations, an oscillator having a resonant circuit actuated by said electrical pulsations to produce a varying frequency, amplifying means for said varying frequency, and an engraving tool actuated by the output from said amplifying means.

2. An apparatus for making printing plates orengravings, comprising means to scan a picture or negative, means to translate the picture shadings into electrical pulsations, a purely electrical os-' cillator actuated by said electrical pulsations to produce a varying frequency, and an engraving tool actuated by said frequency variations.

3. A machine for reproducing a picture on the surface of a plate suit-able for printing, comprising means to scan a picture or a negative, means to translate the shading of the picture into electrical pulsations, an oscillator having a resonant circuit actuated by said electrical pulsations to produce a varying frequency, amplifying means for said varying frequency, an engraving tool actuated by the output from said amplifying means, and means to vary the frequency 'of said oscillator to vary the spacing of the impressions.

4. A machine for making printing plates or engravings comprising means to scan a picture or negative, means to translate the shading of the picture into electrical pulsations, a purely electrical oscillator actuated by said pulsations to produce a varying frequency, an engraving tool actuated by said varying frequency, and means to vary the spacing of the impressions by varying the frequency of the oscillator.

5. In the automatic engraving of a pictorial subject, means for synchronously scanning the subject and engraving a surface, means to translate the picture shadings into electrical pulsations, an oscillator having a resonant circuit actuated 'by said pulsations to produce a varying frequency,

an engraving tool actuated by said varying frequency, and means to vary the level of said varying frequency to vary the depth of the impressions.

6. In the automatic engraving of a printing plate, means for synchronously scanning the picture and engraving the plate, means to translate the picture shadings into electrical pulsations, a purely electrical oscillator actuated by said pulsations to produce a varying frequency, an engraving'tool actuated by said varying frequency, and means to vary the depth of the impressions by varying the amplitude of said varying frequency.

' printing surface, means to translate the picture shadings into electrical pulsations, a purely electrical oscillator actuated by said pulsations to produce a varying frequency, an engraving tool actuated by said varying frequency, and means to vary the spacing of the impressions by varying the speed of the transmitting and the receiving surfaces simultaneously.

9. A machine for making half-tone surfaces for printing in color, comprising means for synchronously scanning the subject photoelectrically and engraving the surface, means for filtering the color characteristics of said subject to produce color separations, means including a, resonant circuit for changing the scanning pulsations into frequency variations, and engraving means responsive to said frequency variations.

10. An apparatus for the engraving of color separation plates suitable for color printing, comprising means for varying the frequency of a purely electrical oscillator in accordance with the lights and shades of the subject to be reproduced as modified by each color filter, and a separate engraving device actuated by the frequency variations.

11. An apparatus for automatic color separation engraving, comprising means for synchronously scanning a colored subject and engraving a printing surface successively for each color, means to modify the light and shade characteristics of the subject with a color filter for each scanning, means including a purely electrical oscillator for changing the modified scanning into frequency variations, and an engraving device responsive to said frequency variations.

12. An apparatus for automatic color separation engraving, comprising means for synchronously scanning a colored subject and engraving a surface simultaneously for each 'color, means for filtering each color simultaneously, means to translate the modified scanning for each color into electrical pulsations, means to amplify the pulsations for each color, means including a resonant circuit for changing each amplified pulsation into frequency variations, and means responsive to said frequency variations to engrave separate surfaces for each color suitable for direct Printing.

ISAAC BRIMBERG. 

